The past 20 years has seen a revolution in personal telecommunications. The clunky brick-like mobile phones used by Wall Street bankers in the 1980s have given way to the magic little boxes in our pockets with previously unimaginable computing power.

Kylie Trengove is a senior analyst at ACMA and one of the contributors to its annual Communications Report. She said the drivers for change in telephony are clearly identifiable.

"There are so many different choices out there for people to communicate, largely because of the role the internet plays," Ms Trengove said.

"People are engaged with their digital lives, they have multiple devices, they can be anywhere and don't need to be at home to contact someone. They can be out on the go and contact people by social media, email, SMS.

"We've also seen that data plans are more generous and inclusions in plans facilitate people using their mobile phones more."

As well as the ubiquity of mobile phones, Ms Trengove points out the proliferation of internet applications for communication.

According to ACMA's Communications Report 2015-16: "In the six months to June 2016, 49 per cent (8.12 million) of online Australians used an app to communicate with others online."

Most of those people prefer to send messages (44 per cent). The report said that a little more than a quarter (27 per cent) made voice calls via an app (such as Skype), while slightly less than a quarter (23 per cent) made video calls via an app.

There is a clear age differential in the data.

Only 12 per cent of Australians over 65 report only using a mobile for their main phone at home. For those aged 25 to 34 that figure is 59 per cent.

While age is a driving force, household circumstance also influences phone use.

Ms Trengove said: "There are some other factors than age. You are more likely to be mobile phone only if you are in a shared household or a boarder."

A spokesperson for ACCAN said: "Consumers going 'mobile-only' is a trend that we believe will continue to grow." However, the organisation is concerned about the impact of this change.

"Fixed-line voice services are particularly important to consumers who live in areas where there is limited or no mobile coverage, or for medical alerts and alarms," the ACCAN spokesperson said. "Consumers in these areas do not have the option of going mobile-only."

Ms Trengove at ACMA said: "The social impacts of these changes is obviously an area the government and ACMA is interested in. This is why we conduct research.

"We look at a whole range of issues, including research into seniors' use of the internet," she said.

"While there is increased connectivity, there are people who are not connected and do not have those options."